Fill in the Blanks UniverseOnline version Fill in the blank spaces to complete the text. by Alexa Fumerton 1 Universe astronomy stars theories Solar Greek galaxy model Milky Universe cosmologies galaxies Throughout recorded history , several and cosmogonies have been proposed to account for observations of the . The earliest quantitative geocentric models were developed by the ancient philosophers . Over the centuries , more precise observations and improved of gravity led to Copernicus's heliocentric and the Newtonian model of the System , respectively . Further improvements in led to the realization that the Solar System is embedded in a composed of billions of , the Way , and that other exist outside it , as far as astronomical instruments can reach . Careful studies of the distribution of these galaxies and their spectral lines have led to much of modern cosmology . Discovery of the red shift and cosmic microwave background radiation suggested that the is expanding and had a beginning .
New game